低能N+注入诱变耐诺氟沙星的金黄色葡萄球菌及其机制分析OA北大核心CSTPCD

The norfloxacin-resistant Staphylococcus aureus was constructed via low-energy N+implantation mutagenesis.Then these strains were examined by whole-genome sequencing,drug-resistance phenotype tests and biofilm analysis methods to explore the mechanism involved in the norfloxacin-resistant S.aureus mediated by low-energy N+implantation.The results showed that 81 norfloxacin-resistant S.aureus strains were screened by low-energy N+implantation mutagenesis.Among which,44 strains appared deletion,in-sertion,point mutation and copy number change of 16S rRNA and antimicrobial resistance genes(ARGs).Further more,the strains with high genetic variety acquired multidrug resistance to different antimicrobi-als,whose resistance to norfloxacin increased by 8 and 16 times,and the biomass,density and matrix pro-tein content of their biofilm were enhanced significantly.These results indicated that low-energy N+im-plantation may cause the sequence variety or copy number changes of 16SrRNA and ARGs in S.aureus,which enhances the biofilm formation ability and the drug efflux protein content,thereby accelerates the formation of drug resistance in S.aureus.